Developing quantum key distribution (QKD) systems using monolithic photonic integrated circuits (PICs) can accelerate their adoption by a wide range of markets, thanks to the potential reduction in size, complexity of the overall system, power consumption, and production cost. In this work, we design, fabricate and characterize an InP-based PIC transmitter for continuous-variable (CV) QKD applications. In a proof-of-principle experiment implementing a pulsed Gaussian-modulated coherent state (GMCS) CV-QKD protocol over an optical fiber channel of 11 km, the system showed a performance compatible with a secret key rate of 78 kbps in the asymptotic regime. These results show the potential of InP technologies to integrate CV-QKD systems onto a monolithic platform.
@article{arxiv.2412.03208,
title = {Integrated InP-based transmitter for Continuous-Variable Quantum Key Distribution},
author = {Jennifer Aldama and Samael Sarmiento and Luis Trigo Vidarte and Sebastian Etcheverry and Ignacio López Grande and Lorenzo Castelvero and Alberto Hinojosa and Tobias Beckerwerth and Yoann Piétri and Amine Rhouni and Eleni Diamanti and Valerio Pruneri},
journal= {arXiv preprint arXiv:2412.03208},
year = {2025}
}